Remote-processing RPC-52 Manuel d'utilisateur télécharger pdf (Page 27)

CHAPTER 9 KEYPAD PORT

Page 25

Figure 9-1 Keypad connector

INTRODUCTION

16, 20, or 24 position keypads are plugged into keypad

port J5. Keys are arranged in a matrix for mat. A key is

recognized when a row and a colum n connect.

RPBASIC-52 scans and debounces the keypad every

debounce time as defined by CONFIG KEYPAD.

Keypad presses are returned as a number from 1 to 24

using the KEYPAD function.

Keypads from Remote Processing simply plug into J5.

The keypad cable length should be limited to less than 5

feet.

PROGRAMMING EXAMPLE

The following example sets up RPBASIC-52 to scan a 16

position keypad. T he results a re echo ' ed when a key is

pressed. C ONF IG KEYPAD is entered in the command

mode. It need be entered only once. Press the 'D' key

to enter.

CONFIG KEYPAD 5

10 STRING 200,20

20 $(0) = "123A456B789C*0#D"

30 P = 1

40 PF = 0

50 PRINT "Enter a number from the keypad",

REM Rest of program continues

REM Scan keypad and update display

200 GOSUB 500

210 IF PF = 0 THEN 200

220 PRINT

230 PRINT "Entered string is: ",$(2)

240 PF = 0

250 GOTO 50

500 A = KEYPAD(0)

510 IF A = 0 THEN 500

520 IF A = 12 THEN 600 : REM Process clear

530 IF A = 16 then 700 : REM process enter

540 A=ASC($(0),A)

550 PRINT CHR(A),

560 ASC($(2),P) = A

570 P = P + 1

580 ASC($(2),P) = 13

590 RETURN

600 REM Clear input string

610 $(2) = ""

620 P = 1

630 RETURN

700 REM Enter processing

710 P = 1

720 PF = 1

730 RETURN

Program explanation

Line 20 defines the keypad legend. Letters may be

redefined as necessary.

Line 30 sets the position counter used to insert characters

into the string.

Line 200 w aits for a key press. The enter ed string is

printed.

Line 500 checks the keypad. If a character is available,

it processes it.

Lines 540-590 update the input string and position. A

< CR> is inserted to mark the end of string.

KEYPAD PORT PI N OUT - J5

The keypad port uses ports B and C from an 82C55.

Lower port C is configured as an input. Upper port C

and port B bits 0 and 1 are outputs.

The table below lists J5' s pin out, 82C55 port and bit,

and its intended function.

Pin 82C55 Function

Port/ bit

1 C/0 Row 1

2 C/6 Column 3

3 C/5 Column 2

4 C/1 Row 2

5 C/2 Row 3

6 C/4 Column 1

7 C/7 Column 4

8 C/3 Row 4

9 B/0 Column 5

10 B/1 Column 6

COMMANDS

The following is a list of RPBASIC-52 commands for

the keypad.

Command Function

CONFIG

KEYPAD Sets keypad parameters

KEYPAD(n) Returns last key from keypad

port

1 2 ... 22 23 24 25 26 27 28 29 30 31 32 ... 35 36

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Remote-processing RPC-52 Manuel d'utilisateur Page 27

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